Cushion mounting for armature in electromagnetic contactor

ABSTRACT

An electromagnetic switching device made of insulation bodies has a molded insulation armature which is apertured to receive a laminated armature having extensions overlying the back edges of the aperture. A cover over the back of the aperture holds the armature in place. Cushions of resilient, shock-absorbing material are inserted between the back cover and the armature.

United States Patent Harold E. Schleicher West Hartford, Conn.

June 17, 1970 Divisional Ser. No. 704,363, Feb. 9, 1968, Patent No.3,551,859

Sept. 28, 1971 Arrow-Hart, llnc.

Hartford, Conn,

Inventor Appl. No. Filed Patented Assignee CUSHION MOUNTING FOR ARMATUREIN ELECTROMAGNETIC CONTACTOR 6 Claims, 5 Drawing Figs.

US. Cl 335/193, 335/249 Int. Cl H0111 3/60 Field 01 Search 335/193,277,271,247, 248, 249, 257, 262; 200/166 H; 248/22 References CitedUNITED STATES PATENTS 1,226,748 5/1917 Burnham 335/247 3,060,355 10/1962Kruzic 335/277 3,453,571 7/1969 Koertge 335/277 Primary Examiner-HaroldBroome Attarney- Davis, Hoxie, Faithful] & Hapgood ABSTRACT: Anelectromagnetic switching device made of insulation bodies has a moldedinsulation armature which is apertured to receive a laminated armaturehaving extensions overlying the back edges of the aperture. A cover overthe back of the aperture holds the armature in place. Cushions ofresilient, shock-absorbing material are inserted between the back coverand the armature.

PATENTEnsEPzemn 3,609,605

FIG. 2

HAROLD E. SCHLEICHER 33 DAVIS, HOXIE, FAITHFULL &

HAPGOOD,

CUSHION MOUNTING FOR ARMATURE IN ELECTROMAGNETIC CONTACTOR Thisapplication is a division of my application Ser. No. 704,363 filed Feb.9, 1968, patented on Dec. 29, 1970, No. 3,55 l ,859.

This invention relates to electromagnetically operated switchingdevices, commonly referred to as electromagnetic contactors. Moreparticularly, the invention relates to an improved and novel mounting ofan armature in a molded, pivoted carrier which controls contactengagement of the contactor.

In electromagnetic contactors as heretofore known, movable contacts havebridged pairs of fixed contacts to open and close the circuits througheach line that is connected to the device. These movable contacts weremounted on a carrier which was caused to move by energization of asolenoid coil, creating an electromagnetic field to attract the armatureagainst a bias of springs or gravity or both.

The constant striking of the armature against the field piece causeswear and damage to the faces of the armature and field piece and shakesthe whole device terrifically. Also, the faces of the armature and fieldpiece sometimes do not mate properly and with maximum effectiveness.This causes heating, annoying hum and loss of energy in the magneticcircuit.

It is an object of this invention to provide improved means to cushionthe armature to absorb the shock of its engagement with the field piece.Another object is to provide improved means for self-alignment of thearmature as it engages the field piece. Another object is to provideimproved means for quick assembly of the armature in its carrier, whichat the same time will permit achievement of said other objectives of theinvention. In the drawings:

FIG. 1 is a side elevation view of an electromagnetically ac tuatedswitch or contactor embodying the invention.

FIG. 2 is an elevational section view of the invention as illustrated inFIG. 1, taken along a central longitudinal plane.

FIG. 3 is a perspective view of the movable contact-actuating assemblyused in the invention as illustrated in FIG. 1.

FIG. 4 is a vertical section view along line 4-4 of FIG. 3.

FIG. 5 is a transverse section view taken along line 5-5 of FIG. 3.

The invention as illustrated in the drawings is made up of severalinterconnected assemblies each having a number of parts.

The assemblies are mounted on a base made of molded insulating material.These assemblies are:

l. A base assembly comprising an insulation base member on which aremounted fixed contacts and terminal members.

2. A movable contact assembly which is mounted in the base and includesan insulation contact carrier on which is mounted a plurality ofbridging contacts, each adapted to engage and disengage a pair of fixedcontacts.

3. An actuating assembly for moving the movable contact carrierincluding a pivoted U-shaped bellcrank level member carrying anelectromagnet armature. A field assembly for an electromagnet includingan insulating body on which is mounted a subassembly consisting of asolenoid coil embedded in insulation and a laminated U-shaped fieldpiece passing through the coil.

5. A cover made of insulation for the electromagnet field assemblymounted on the same.

The details of the electromagnetic contactor are fully described andclaimed in parent application Ser. No. 704,363, to which reference maybe had for understanding of its details. Hence, the contactor isdescribed herein only to the extent necessary to understand the relationof its parts to the armature mounting improvements claimed herein.

THE BASE MEMBER Referring more particularly to the individual componentsor assemblies which make up the contactor, the base 10 is a moldedinsulating body of a generally rectangular shape and is hollowed outwith three parallel similar cavities for the reception of pairs ofaligned fixed contact and terminal members such as 12b.

On one end of each member (the inner end, as viewed in FIG. 2), is acontact button such as 12c, while the other end extends toward theoutside of the base and has a terminal screw 12! threaded through it.

The fixed contacts and terminal members are secured to the base byscrews 12s.

MOVABLE CONTACT ASSEMBLY The movable contact assembly consists of anelongated molded insulation carrier 20 supporting a stamped sheet metalbridging contacts such as 24, the base cavities and their walls beingmolded to receive the guide the carrier in movement toward and from thefixed contacts.

Pressing against each end of the bridging contact are the coilcompression springs, the other (upper) ends of the springs pressingagainst lateral extensions from the carrier 20.

For moving the contact carrier there is an endwise extension 28 fromeach end thereof, embraced by forked ends of the arm 31 of an armatureassembly 30, as hereinafter described.

To bias the contact carrier 20 and the armature assembly, spring-pressedplungers 27 (see FIG. 1) are mounted in two symmetrically located wells,one in each of the walls of the base beneath each end of the contactcarrier. Each of these plungers is pressed upwardly against the bottomtyne of the forked end of the arms 31 of the armature assembly 30, as inFIGS. 1 and 2, by a coiled compression spring 29 seated in the well andreceived in the hollow head of its plunger 27.

ELECTROMAGNETIC CONTACT-ACTUATING MEANS This means consists of twoassemblies: l an electromagnet field assembly consisting of (a) asupporting member or body 40, (b) a solenoid coil and field piece; and(2) an armature as sembly, as will become apparent as these assembliesare described. They may be assembled with ease on the base 10 asindividual self-contained units; and equally they may be disassembledfrom the base.

1. The Field Assembly a. The Supporting Member. This consists of aninsulating support member or body 40 formed from molded insulationmaterial into the form best observed in FIGS. 1 and 2. The body is ofirregular shape but symmetrical about its longitudinal centerline.Viewed from the side (as in FIG. I), it has generally rectangular sideswith generally triangular platelike extensions 42 at the end of each ofits sides. The extensions taper to tips 42' which when the body 40 isassembled upon the base end, extend under over hanging projections 18,which extend up from the base at two opposite comers thereof. The widthof the body 40 approximates that of the base; and the surfaces of thebottom body lie in a plane and on the top surface of the base 10. Thebody 40 is located in proper position top of the base by conical collars19 extending up around screwbolt passages through the base from the topsurface of the base at those corners of the base which are opposite tothe tips 42'.

Referring to FIG. 2, on the inside of each of the projections 18 on thebody 40 there is a vertical wall closing the inner side of the overhand.This prevents sidewise movement of the tips 42' when they are engagesunder the overhand.

The bottom of the body 40 overlies trunnion recesses 16 in the base 10and the trunnions 32 of the hereinafter describedarmature assembly, thusholding the trunnions in the recesses.

b. The Solenoid Coil and Field Piece. A solenoid coil is embedded andcompletely encases in a casing 51 of molded insulation material. Thecoil may include two identical torroidal units.

The coil-encasing housing is molded with two parallel passagewaysthrough the axes of the coils for reception of a laminated U-shapedfield piece 58, the back face of the transverse portion thereof beingfiat.

To cushion the fieldpiece against the shock of the armature strikingagainst it, as hereinafter described, a slot is molded in thefield-supporting body 40, located behind the flat rear face of the fieldpiece, running along the whole length of said rear face and beyond. Inthis slot a ripple-type leaf spring 59 is placed edgewise so that itsundulating opposite surfaces will press against the surface of the slotand against the rear facing of the field piece, at a plurality of pointssymmetrically.

To hold the field unit in the body 40, a shallow flat-topped cover 60 ofmolded insulation material is secured over the field units by bolts 61which pass downwardly through holes in the cover into the body 40 nearneighboring corners. The cover is hollowed in under surface to receivein close-fitting embrace the upper part of the coil casing 51, as may beseen in FIG. 2.

2. The Actuating Assembly To actuate the movable contact carrier, abellcrank-type electromagnet armature assembly 30 is mounted in the basepivotally in open V-shape recesses 16 that are provided in the sidewallsof the base in opposite aligned positions.

The body of the assembly is made of molded insulation and, as may beseen best in the perspective view of FIG. 3, is generally speaking ofU-shape, with its arms formed identically in the shape of parallelbellcrank levers 31. Trunnions 32 extend from the outer side surfaces ofthe arms 31 for seating in the V-recesses 16 in the sides of the base.The ends of the anns 31 are forked to embrace the extending ends 28 ofthe contact carrier, as previously mentioned, to cause the carrier andbridging contacts 24 to move toward and away from the fixed contacts12c. The armature assembly is biased toward inactive position asshown,in FIGS. 1 and 2 by the springpressed plungers 27 pressing againstthe bottom side of the forked ends of the arms 31 in those figures, allas previously mentioned.

The transverse part 33 of the armature assembly has a rectangularopening through it and extending longitudinally along it. The opening islonger at its rear than at its front, roviding shoulders 35 at each end.(See FIG. 4). In the opening is inserted a rectangular laminated barannature 36 with raised machined faces 36 on its front adjacent eachend, to engage the ends of the field piece. The armature laminations areotherwise of substantially the same configuration as the opening(viewing its section in FIG. 4 wherein is seen lamination) so that theshoulders 36: on it (see FIG. 4) will rest on the shoulders 35 of theopening to hold the armature bar in place. The shoulders 35 have radialsurfaces, as shown in FIGS. 2 and 5 (in dotted lines), to permit thearmature, when assembled, to align with the magnet pole faces by limitedrocking movement. A back plate 39 of insulating material is secured byscrews 38 to the body 33. Between the backplate and annature bar acushioning pad 37a of rubber or other suitable shock-absorbing resilientmaterial may be placed; and similar cushioning pads 37b may be placedbetween the upper and lower faces of the bar and the adjacent boundariesof the opening in the transverse part 33 of the body.

The cushioning of the armature bar 36 and the resilient support of thefield piece 58 to shocks, also enables the annature and field piece toalign themselves for optimum engagement and magnetic circuitry.

To cushion and dampen the opening movement of the armature assembly 30as it drops open under urge of the biasing springs 29, two dampingfingers 19x made of molded synthetic plastic materials in tapered thinstrip form are placed in slots in the base 10 (see FIG. 1) in positionto be engaged by opof the movin armature seating in attracted position.

Many mo ifications within the scope of the invention WI" occur to thoseskilled in the art. Therefore, the invention is not limited to thespecific embodiment illustrated and described.

What is claimed is:

1. In an electromagnetic contactor having fixed contact means, andmovable contact means engageable with and separable from said fixedcontact means, electromagnetic operating means including a pivotallysupported armature means, a field piece and a solenoid coil which, whenenergized, causes movement of the armature and said movable contacts,said armature means comprising a pivotally mounted carrier of moldedinsulation material having a cavity therein for a laminated armature, alaminated armature seated in said cavity, cushioning means on threesides of said armature enabling the armature to adjust itself within itssupport to said field piece upon engagement with the latter.

2. In an electromagnetic contactor, as claimed in claim 1 in which saidarmature has opposite lateral extensions, said carrier having recessesfor said extensions with curved supporting surfaces on which saidextensions seat to facilitate said adjustment.

3. In an electromagnetic contactor, as claimed in claim 2, in which saidcarrier has a passage therethrough in which said armature is insertedfrom one side, a cover secured over said passage retaining said armaturetherein.

4. In a electromagnetic contactor, as claimed in 1, in which saidcarrier has a passage therethrough in which said armature is insertedfrom one side, a cover secured over said passage retaining said armaturetherein.

5. In an electromagnetic contactor having fixed contact means, andmovable contact means engageable with and separably from said fixedcontact means, electromagnetic operating means including a pivotallysupported armature means, a field piece and a solenoid coil which, whenenergized, causes movement of the armature and said movable contacts,said armature means comprising vertically mounted carrier of moldedinsulation material having a cavity therein for a laminated armature, alaminated armature seated in said cavity, said armature having oppositelateral extensions, said carrier having recesses for said extensionsseat to facilitate said adjustment.

6. In an electromagnetic contactor, as claimed in claim 2, wherein saidcarrier-cavity is a passage through which said armature is inserted oneside, a cover secured over said passage retaining said armature therein.

1. In an electromagnetic contactor having fixed contact means, andmovable contact means engageable with and separable from said fixedcontact means, electromagnetic operating means including a pivotallysupported armature means, a field piece and a solenoid coil which, whenenergized, causes movement of the armature and said movable contacts,said armature means comprising a pivotally mounted carrier of moldedinsulation material having a cavity therein for a laminated armature, alaminated armature seated in said cavity, cushioning means on threesides of said armature enabling the armature to adjust itself within itssupport to said field piece upon engagement with the latter.
 2. In anelectromagnetic contactor, as claimed in claim 1 in which said armaturehas opposite lateral extensions, said carrier having recesses for saidextensions with curved supporting surfaces on which said extensions seatto facilitate said adjustment.
 3. In an electromagnetic contactor, asclaimed in claim 2, in which said carrier has a passage therethrough inwhich said armature is inserted from one side, a cover secured over saidpassage retaining said armature therein.
 4. In a electromagneticcontactor, as claimed in 1, in which said carrier has a passagetherethrough in which said armature is inserted from one side, a coversecured over said passage retaining said armature therein.
 5. In anelectromagnetic contactor having fixed contact means, and movablecontact means engageable with and separably from said fixed contactmeans, electromagnetic operating means including a pivotally supportedarmature means, a field piece and a solenoid coil which, when energized,causes movement of the armature and said movable contacts, said armaturemeans comprising pivotally mounted carrier of molded insulation materialhaving a cavity therein for a laminated armature, a laminated armatureseated in said cavity, said armature having opposite lateral extensions,said carrier having recesses for said extensions with curved supportingsurfaces on which extensions seat to facilitate said adjustment.
 6. Inan electromagnetic contactor, as claimed in claim 2, wherein saidcarrier-cavity is a passage through which said armature is inserted oneside, a cover secured over said passage retaining said armature therein.